A device driver is a computer program that controls or operates one or more hardware components in a computing system. The device driver provides a software interface between the hardware components and an operating system and/or applications and utilities. Device drivers and the operating system components may interact via function calls, such as application programming interfaces (APIs) function calls that are published and updated over time by the operating system vendor, the hardware vendor, or standards groups; and function callbacks by an operating system component to function addresses provided by the device driver.
Many device drivers are written by software developers of assorted hardware vendors to work in a variety of operating system environments, although other software developers may also write device drivers. Device driver developers may inadvertently or maliciously introduce improper operations into the device drivers, which may result in computer crashes, performance issues, and/or security breaches. These improper operations typically surface when functions are called improperly (e.g., with the wrong parameters, in the wrong sequence). Verifying proper device driver operation is a challenging yet important responsibility of modern computing systems.